High Blood Pressure (Hypertension)

High blood pressure (hypertension) is a common condition in which the force of blood pushing against your artery walls is consistently too high. This makes your heart work harder to pump blood. Over time, hypertension damages your blood vessels and heart, leading to serious complications, like a heart attack or stroke.

Common causes include genetics, aging, smoking and not getting enough physical activity. Certain underlying medical conditions can also cause it. Often, high blood pressure doesn’t have symptoms until it causes sudden harm to your heart, kidney or brain. That’s why it’s called a “silent killer.”

It’s a cardiovascular disease risk factor that affects about 1 in 2 adults in the U.S.

Lifestyle and dietary changes — like moving around more and reducing sodium intake — can lower your blood pressure (BP) to a safer level. You may also need antihypertensive medications and/or treatment for underlying conditions.

Healthcare providers measure blood pressure in millimeters of mercury (mmHg). A normal BP is below 120/80 mmHg. The hypertension threshold varies based on where you live. In the U.S., providers define it as:

• A top number (systolic BP) of 130 mmHg or higher, OR
• A bottom number (diastolic BP) of 80 mmHg or higher

A systolic BP between 120 and 129 mmHg is considered “elevated blood pressure” and can develop into hypertension with time.

In Europe, providers define hypertension as a top number of 140 or higher, or a bottom number of 90 or higher.

Stages of high blood pressure

There are two main stages of hypertension:

• Stage 1: Your top number is in the 130s, OR your bottom number is in the 80s.
• Stage 2: Your top number is 140 or higher, OR your bottom number is 90 or higher.

Blood pressure that’s above 180/120 mmHg is dangerously high. Healthcare providers use these terms to describe it:

• Severe hypertension: Your top number is 180 or higher, OR your bottom number is 120 or higher. But you don’t have any symptoms.
• A hypertensive emergency: High blood pressure is damaging your organs and causing symptoms, like chest pain, seizures or a severe headache. This is a medical emergency that requires immediate care.

What causes high blood pressure?

Multiple factors affect blood pressure. It’s normal for your blood pressure to fluctuate during the day, as your nervous system is one factor that affects it. Having excess fluid in your circulatory system will also increase your blood pressure. This might happen if you eat a lot of salty foods, which draw in fluid. Finally, kidney function and regulatory hormones in your body also affect blood pressure.

There are two main types of high blood pressure based on the specific underlying causes: primary hypertension and secondary hypertension.

Primary hypertension

For this type, there isn’t a specific, separate driver behind the high blood pressure, like your kidneys, hormones, medications or nervous system. Instead, many factors — like aging, genetics and family history — come together to raise it. Primary hypertension may develop gradually over time.

Secondary hypertension

A medical condition, medication or addictive substance raises your blood pressure, often within a short period of time. Common causes include:

• Obstructive sleep apnea
• Renal artery stenosis (narrowed kidney arteries)
• Medications, like antidepressants, immunosuppressants and NSAIDs
• Alcohol, nicotine or recreational drugs

Other types of hypertension

You might also hear about high blood pressure that occurs in certain situations:

• White coat hypertension: Your BP is normal at home but high in a healthcare setting due to stress or anxiety about the appointment. Your healthcare provider may ask you to check your blood pressure at home. Or they may prescribe an ambulatory blood pressure monitor for you to wear around the clock. 
• Masked hypertension: Your BP is normal in a healthcare setting but high at home. Your healthcare provider may suspect this if your heart or kidneys show evidence that they’ve been affected by high blood pressure.
• Nocturnal hypertension: Your BP goes up when you sleep. An ambulatory blood pressure monitor can identify this.
• Resistant hypertension: Your BP remains high despite taking at least three blood pressure medications, or you need at least four blood pressure medications to keep it managed.

Risk factors for high blood pressure

There are many risk factors for hypertension, including:

• Being over age 55
• Having a history of hypertension in your biological family
• Smoking or using tobacco products
• Having overweight/obesity
• Eating foods high in sodium
• Not getting enough physical activity
• Drinking too much alcohol
• Using stimulant drugs, like amphetamines, that aren’t prescribed for you (this can cause dangerous BP spikes)

High blood pressure symptoms

High blood pressure usually doesn’t have symptoms. It’s not something you can typically feel. You could have high blood pressure for years without any clues. The World Health Organization estimates that 44% of adults with hypertension don’t know they have it. 

If your blood pressure is extremely high, you may have symptoms, like:

• Confusion, disorientation or other changes to your thinking
• Chest pain
• Dizziness
• Edema (swelling)
• Heart palpitations
• Peeing less than usual
• Seizures
• Severe headache
• Signs of stroke, like a sudden facial droop, slurred speech or sudden arm/leg weakness
• Vision changes, like eye pain, vision loss or sudden blurry vision

This is called a hypertensive emergency. Call 911 or your local emergency number right away if your blood pressure is 180/120 or higher and you have any of the symptoms above. If you’re pregnant, call for help if your BP is 160/110 or higher with symptoms.

How doctors diagnose this condition

A healthcare provider will review your medical history, do a physical exam and check your blood pressure using a cuff they wrap around your arm. You’ll feel a brief squeeze as the cuff tightens around your arm. Your provider may measure your BP more than once at the same appointment. They’ll diagnose you with hypertension if your numbers are high at two separate visits (with at least two readings taken each time).

Your blood pressure reading has two numbers:

• Top number (systolic blood pressure): This is the pressure on your artery walls when your heart beats.
• Bottom number (diastolic blood pressure): This is the pressure between beats when your heart relaxes.

It’s common for both your top number (systolic) and your bottom number (diastolic) to be too high. But it’s also possible for just one to be in the hypertensive range. You might hear your provider use these terms to describe your blood pressure:

• Isolated systolic hypertension: Your top number is 130 or higher, but your bottom number is below 80. This is more likely to happen as you get older and your arteries get stiffer.
• Isolated diastolic hypertension: Your bottom number is 80 or higher, but your top number is below 130. This is less common overall and typically affects younger adults.

How is high blood pressure treated?

Hypertension treatments include medications to lower your blood pressure and changes to your daily habits (lifestyle changes). Common medications prescribed for high blood pressure include diuretics, beta-blockers, calcium channel blockers, ACE inhibitors and ARBs. Your healthcare provider will recommend the right treatment plan for you based on your blood pressure readings, the cause of high blood pressure and any other conditions you may have.

In general, lifestyle changes are a key part of treatment for everyone. This is true even if you’re taking medicine. In some cases, providers recommend making changes for a while before starting medication. It depends on your medical history and risk for a heart attack or stroke.

Changes you can make include:

• Maintain a weight that’s healthy for you. Your healthcare provider can give you a target range. Maintaining a healthy weight can help reduce your heart’s workload and lower your blood pressure.
• Eat nutritious foods. Your provider may recommend the DASH diet, which is an evidence-based eating plan for lowering blood pressure. It involves eating lots of fruits, veggies and whole grains while limiting salt, saturated fat and added sugar.
• Cut down on sodium. Try to limit your daily sodium intake to 1,500 milligrams (mg). Consuming too much sodium causes your body to retain water, which raises your blood pressure.
• Get enough potassium. Try to get 3,500 to 5,000 mg per day. Ideally, this should be through foods rather than supplements. Potassium helps your body get rid of excess sodium and helps your blood vessel walls to relax, lowering BP.
• Get enough sleep. Healthy sleep is important for your blood pressure and heart health.
• Get enough physical activity. Ask your healthcare provider what’s safe for you and how to get started. In general, work your way up to 150 minutes of aerobic exercise per week.
• Quit smoking. Quitting lowers your blood pressure and has many other benefits.
• Limit or avoid alcohol. The less alcohol you drink, the better for your blood pressure and entire circulatory system.

When should I see my healthcare provider?

See your healthcare provider for yearly check-ups so they can measure your blood pressure and look for changes over time.

Call your provider if you notice your BP is higher than usual when you check it at home. They may ask you to come in so they can measure it.

If you’re pregnant, call your provider if your BP is ever 160/110 or above — but if you have symptoms, seek emergency care instead.

What can I expect if I have high blood pressure?

You’ll work with your healthcare provider to manage high blood pressure and reduce the risk of complications. This may involve taking medication. Be sure to take it exactly as your provider prescribes. Don’t skip doses or stop taking your meds unless your provider says to. Skipping or stopping without consulting your provider can lead to a hypertensive emergency.

Complications of long-term high blood pressure

Over time, untreated hypertension may lead to:

• AFib: A chaotic rhythm in your heart
• Chronic kidney disease: Problems with your kidney function
• Cognitive impairment and dementia: Changes to your thinking, memory and personality
• Coronary artery disease: Narrowed or blocked arteries in your heart
• Heart attack: A sudden lack of blood flow to your heart
• Heart failure: A long-term condition that affects your heart’s pumping ability
• Hypertensive retinopathy: Damage to your eyes that may lead to vision loss
• Peripheral artery disease: Narrowed or blocked arteries in your legs or arms
• Erectile dysfunction: Difficulty in obtaining an erection
• Stroke: A sudden lack of blood flow to your brain